1. Field of the Invention
The present invention relates to a xylanase composition with increased stability, and the method for manufacturing the same.
2. Descriptions of the Related Art
Enzymes are proteins which can function as bio-catalysts and can be widely applied in various chemical reactions to increase the rate of reaction.
Inactive enzymes are costly for researchers and factory owners because once an enzyme is inactivated and loses its function, it cannot exert its intrinsic catalytic action. As a result, researchers or factory owners have to pay additional costs to increase the amount of the enzyme used or purchase new enzymes for replacement to achieve the desired efficiency.
Therefore, a method or a formulation that prevents enzymes from being inactivated due to environment factors, such as high temperature, or increases the stability of enzymes during storage or transport is urgently desired in the industry.
Xylanase is the main enzyme that degrades hemicellulose among sugar hydrolysis enzymes, and is widely applied in various fields such as foods, animal feeds, textiles or papermaking. For example, xylanase may be used to treat chicken feed to degrade anti-nutrient factors in the feed, thereby, promoting the uptake of nutrient and the growth of chickens. In addition, if xylanase is added in the dough, the mechanical strength of the dough may be improved, and its appearance and storability can also be improved accordingly.
A method for increasing the stability of xylanase from aerobic fungi has been disclosed in the literature, which improves the storability of xylanase by using a formulation comprising a polyol, salts and antibiotics (Fisk et al. 1992. Development of A Method for the Stabilization and Formulation of Xylanase from Trichoderma Using Experimental Design. Studies in Organic Chemistry, 47: 323-328, which is incorporated hereinto by reference). However, according to the literature, the stabilizing effect (e.g., the stabilizing duration and temperature) provided by the formulation is quite limited. The activity of xylanase from an aerobic fungus, Trichoderma, was at about 80% after 42 hours under 48° C.
As known by persons with ordinary knowledge in the art of enzymes, different enzymes have different characteristics, such as the structure, heat resistance, or optimum storage condition, etc. The interaction between different enzymes and the same compound or formulation is also different. Therefore, it has been indicated in literatures that for different enzymes, the same component or formulation cannot provide the same stabilizing effect, and polyols do not necessarily provide a stabilizing effect (Asther et al. 1990. Increased thermal stability of B. licheniformis alpha-amylase in the presence of various additives. Enzyme and Microbial Technology. 12: 902-905, which is incorporated hereinto by reference).
Among the known xylanses from different sources, xylanases from anaerobic fungi (also called rumen fungi) are the most interesting because anaerobic fungi generally grow in the rumen (such as the digestive tract of ruminants or herbivores with a single stomach) in which competition stress for survival is high. Thus, these fungi have evolved to produce xylanases with high activity (Anthony et al. 1994. Anaerobic fungi in herbivorous animals. Mycol. Res. 98: 129-152, which is incorporated hereinto by reference). Compared to general xylanases, xylanases from anaerobic fungi are more widely applicable due to their advantages, such as high enzyme activity, high specificity, heat resistance, etc. Hence, a method for preserving xylanases from anaerobic fungi effectively is required for persons in this field to prevent the enzyme activity from decreasing during the storage.
The present invention provides a composition for increasing the stability of xylanase from anaerobic fungi. The inventors of the present application found that a composition comprising polyols with specific components and ratio can achieve the effect of significantly increasing enzyme storability.